Clang: Use std::unique_ptr instead of QScopedPointer

std::unique_ptr is in the standard and QScopedPointer maybe gets
depreciated in futur. So lets use std::unique_ptr instead so we don't have
to change to much code later.

Change-Id: Id479b0e80adaf3da4e408198d43c5dfd09a8c66d
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/libs/clangbackendipc/connectionclient.cpp

@@ -112,7 +112,7 @@ QProcessEnvironment ConnectionClient::processEnvironment() const
 
 const QTemporaryDir &ConnectionClient::temporaryDirectory() const
 {
-    return *temporaryDirectory_.data();
+    return *temporaryDirectory_;
 }
 
 LinePrefixer &ConnectionClient::stdErrPrefixer()

src/libs/clangbackendipc/connectionclient.h

@@ -125,7 +125,7 @@ private:
 
     mutable std::unique_ptr<QProcess> process_;
     QLocalSocket localSocket;
-    QScopedPointer<QTemporaryDir> temporaryDirectory_;
+    std::unique_ptr<QTemporaryDir> temporaryDirectory_;
     QTimer processAliveTimer;
     QString processPath_;
     bool isAliveTimerResetted = false;